JP2005051239A - Reconnectable chip interface and chip package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reconnectable chip interface and a chip package. <P>SOLUTION: Electrical connection pads 23, 27 on a circuit device and on a substrate are brought into contact with each other when the circuit device and the substrate are connected to each other. At least a single first protrusion 37 on one of the device and the substrate and at least two second protrusions 39 on the other of the device and the substrate have their lengths in the axial direction. The protrusions are so sized and shaped as to be closely friction-fit along their axial lengths when they engage with each other. The integrated circuit device package includes an integrated circuit device and an interconnection board for mounting the integrated circuit device on an electronic circuit board. The interconnection board forms an enclosed space which is combined with the active surface of the integrated circuit device for the formation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates generally to integrated circuit assemblies, and more particularly to electro-mechanical connections between a microchip and a substrate. The invention also relates to an integrated circuit device package for protecting an integrated circuit device, and a process for forming such a package.

  Integrated circuit devices (i.e., microchips, chips or dies) are typically attached to a substrate (e.g., chip carrier, package or circuit board) in a well-known manner, such as direct chip attach (DCA) or wire bonding. Connected using. DCA uses bonding materials typically applied to the electrical connection pads (ie, bond pads) of the chip, such as metallurgical solder or polymeric conductive adhesive. The chip is then electromechanically connected to corresponding bond pads on the substrate by applying heat to melt or reflow the solder. A protective polymer called underfill is applied to the gap between the chip and the substrate and then cured by heating. As a result, the liquid polymerizes into a solid, providing further bonding between the chip and the substrate. In wire bonding, an adhesive or solder is used to attach a chip to a substrate. After chip attachment, thin metal wires are welded to the electrical connection pads of each chip as well as to the electrical connection pads of the corresponding substrate using heat or ultrasonic energy. Reference is made to US Pat. Nos. 5,439,162 and 5,665,654. Both of these are hereby incorporated by reference for additional background information regarding the DCA and wire bonding attachment process for all purposes. Although the DCA and wire bonding process typically produces a reliable chip connection, this connection is considered permanent and does not allow chip removal and reconnection. Also, the heat required to reflow solder and adhesive frequently damages the microchip and reduces manufacturing efficiency.

  The existing electro-mechanical chip connection method that eliminates the thermal bonding process is that traditional microchip devices are electrically and mechanically mounted on the circuit board, removing the chip without heating the chip or board. And be able to be reconnected. These conventional electro-mechanical connection methods involve metallized interlocking structures (ie hook and loop configurations, locking inserts and sockets, interlocking microstructured barbs disposed on the microchip and substrate electrical connection pads. ) Is typically included. Reference is made to US Pat. Nos. 5,411,400, 5,774,341 and 5,903,059. These are hereby incorporated by reference for additional background information regarding existing reconnectable electro-mechanical connections between electronic devices and substrates for all purposes. Existing reconnectable chip interface structures do not appear to be widely accepted in industry due to high manufacturing costs and low operational reliability.

  MEMS, or micro electro mechanical systems, are often integrated circuit devices with moving parts, or microstructures that can move material (as in a thermal inkjet chip). A common requirement for packaging MEMS devices is that there is no encapsulant or enclosure that can contact the active surface or surface of the chip. Even with integrated circuit devices that have no moving parts, such as radio frequency components including inductor coils, packages with free space are well served. This is because the capsule material “detunes” the high frequency device. DCA cannot be used to connect a MEMS device directly to an electronic substrate. This is because the underfill applied to the area between the chip and the substrate covers the active surface. Unfortunately, transfer molding, a traditional low-cost packaging method, applies plastic encapsulant to the entire chip surface, making most MEMS devices useless. The same applies to the liquid capsule material applied by needle dispensing. Currently, there is no effective low cost packaging method for MEMS devices.

  The most common package for MEMS devices and other integrated circuit devices is a metal or ceramic hermetic enclosure, which is conceptually considered a small box that is lidded after the chip is inserted and connected. It is. This increases the cost and limits the number of connections, since the insulated electrical leads must pass outside the box. These existing sealed enclosures are made of metal or ceramic and cost about 10 to 100 times as much as transfer molded plastic packages. The sealed lid must be welded, soldered or brazed, which heats the normally heat sensitive device within the enclosure. Typical metal or ceramic sealed enclosures are typically much larger than the size of the chip and require more circuit board mounting space than if the chip were mounted directly on the board.

  An alternative chip packaging design called Chip Scale Package (CSP) reduces the size of the package so that less circuit board space is required. Existing CSP designs have a cap attached to a base substrate on which the integrated circuit device is mounted. A gasket or adhesive layer around the periphery of the electrical connection pads on the base wafer bonds and seals the cap to the wafer, providing an enclosure that is significantly larger than the active surface of the integrated circuit device. Reference is made to US Pat. Nos. 6,228,675 and 6,441,481. These are hereby incorporated by reference for additional background information on existing CSP designs for all purposes. Existing CSP designs lack interconnects for direct electrical connection to the circuit board. As a result, the microchip with the cap needs to undergo an interconnection process (for example, wire bonding) after the cap and the base substrate are coupled. In general, a chip scale package (CSP) is defined as a chip package in which the total package size does not grow more than about 20% larger than the size of the circuit device encapsulated within the package. As technology is driven towards advanced miniaturization, CSP designs with sizes near the 20% guideline will become insufficient to meet the miniaturization requirements of the electronics industry. Therefore, there is a need for simple microchip packages that are more economical and reliable than existing ceramic packages, as well as microchip packages that are easier to manufacture and smaller than existing ceramic packages.

[Disclosure of the Invention]
Some of the objects of the present invention are to provide an assembly that allows an electromechanical connection of an integrated circuit device to a substrate at ambient temperature, allowing for economical manufacturing. Provide similar assemblies, provide similar assemblies that allow simple testing, provide similar assemblies that allow easy rework, and allow easy removal and replacement of integrated circuit devices And providing a similar assembly.

  Further, some of the objects of the present invention are to provide a package that is simple to manufacture to protect integrated circuit devices, to provide a similar package with a small scale, and to a substrate. Providing similar packages that allow reliable electrical and mechanical connections, providing similar packages that provide sufficient protection space for circuit devices, and providing similar packages that reduce assembly processes And the provision of a similar package that allows a reconnectable electrical connection to an electronic circuit board.

  In general, the assembly of the present invention comprises a substrate and an integrated circuit device adapted to be electrically and mechanically connected to the substrate. A first set of electrical connection pads on the circuit device and on the substrate is applied to contact each other when the circuit device and the substrate are connected. The set of connection pads has at least one first protrusion on one of the device and the substrate and at least two second protrusions on the other of the device and the substrate. Each protrusion has a respective axial length extending from the outer surface of the respective connection pad. The first protrusion and the second protrusion are sized and shaped to have a close frictional fit along their axial length when the protrusions are engaged with each other, thereby An electrical and mechanical connection is established between the device and the substrate.

  Another form of assembly of the invention comprises a substrate having a plurality of connection pads. Each pad has a plurality of spaced apart conductive protrusions. These protrusions extend from the outer surface of the pad and form an open space between them. The integrated circuit device is adapted to be electrically and mechanically connected to the substrate. The device has a plurality of connection pads. Each pad includes at least one conductive protrusion extending from the outer surface of the pad. Conductive protrusions on the device are applied for insertion into the open space. Thus, the device and the substrate are held in an electrical and mechanical connection by a friction fit between the respective protrusions.

  Another form of assembly of the invention comprises a substrate and an integrated circuit device adapted to be electrically and mechanically connected to the substrate. The first connection pads on the substrate comprise a first set of two or more conductive connection elements protruding from the outer surface of one pad. Each connecting element of the first set has an axial length generally orthogonal to the substrate. The second connection pad on the substrate comprises a second set of one or more conductive connection elements protruding from the outer surface of the pad. Each connecting element of the second set has an axial length and is applied to the engagement of the connecting element with the first set of connecting elements. The first and second sets of connecting elements are sized and shaped to provide a tight friction fit along their respective axial lengths when engaged with each other, whereby the device and the Establish electrical and mechanical connections with the substrate.

  In general, an integrated circuit device package of the present invention has an active surface with at least one electrical connection pad thereon and an integrated circuit device for mounting on an electronic circuit board. Interconnect substrate. The interconnect substrate is applied to electrical and mechanical connections between the electronic circuit board and a first surface applied to be combined with an active surface of the integrated circuit device to form an enclosed space. And a second surface. The interconnect substrate has at least one set of electrical connection pads, each set being adapted for electrical connection with at least one electrical connection pad on the integrated circuit device. A first electrical connection pad on one surface; and a second electrical connection pad on the second surface of the interconnect substrate electrically connected to the first connection pad. The second electrical connection pads on the second surface of the interconnect substrate are applied for electrical and mechanical connection with the electronic circuit board.

  Another form of integrated circuit device package of the present invention comprises an integrated circuit device having an active surface and having at least one electrical connection pad thereon. An interconnect substrate for mounting the integrated circuit device on the electronic circuit substrate includes a first surface adapted to be combined with an active surface of the integrated circuit device to form an enclosed space, and the electronic And a second surface applied for electrical and mechanical connection with the circuit board. The interconnect substrate has at least one set of electrical connection pads, each set being adapted for electrical connection with at least one electrical connection pad on the integrated circuit device. A first electrical connection pad on one surface; and a second electrical connection pad on the second surface of the interconnect substrate electrically connected to the first connection pad. The second electrical connection pads on the second surface of the interconnect substrate are applied for electrical and mechanical connection with the electronic circuit board.

  Another aspect of the invention relates to a process for forming an integrated circuit device scale package. The process includes the steps of creating an integrated circuit device wafer having an active surface and an interconnect substrate wafer such that the wafer has electrical connection pads on its opposing surface and has a single concave surface. And a step of creating. The integrated circuit device wafer and the interconnect substrate wafer are electrically and mechanically connected, and the two wafers are enclosed between an active surface of the integrated circuit device wafer and a recessed surface of the interconnect substrate wafer. Form a space. The integrated circuit device wafer and the interconnect substrate wafer are diced to form one or more individual integrated circuit device packages.

  According to another aspect of the present invention, there is provided an interconnect substrate for mounting an integrated circuit device on an electronic circuit substrate, and forming an enclosed space in combination with an active surface of the integrated circuit device. And a second surface applied for electrical and mechanical connection with the electronic circuit board. A first electrical connection pad on the first surface of the interconnect substrate is applied for electrical connection with the integrated circuit device. A second electrical connection pad on the second surface of the interconnect substrate is electrically connected to the first connection pad. The second electrical connection pads on the second surface of the interconnect substrate are applied for electrical and mechanical connection with the electronic circuit board.

  Other objects and features will be in part apparent and in part pointed out hereinafter.

  With reference to the drawings, and in particular with reference to FIG. 1, the chip module shown in schematic 1 comprises an integrated circuit device assembled in accordance with the present invention shown in schematic 3. In the particular embodiment of FIG. 1, the module 1 is attached to a conventional ball grid array 5 having solder balls 9 for electrical connection to a printed circuit board (not shown). The point to be understood here is that the chip module 1 can be directly attached to the circuit board, or can be attached via another normal connection board (for example, pin grid array or land grid array). is there. The module 1 can also contain more than one integrated circuit device 3 assembled according to the invention.

  As shown in FIGS. 1 and 2, the integrated circuit device 3 of the module 1 is electrically and mechanically attached to a chip carrier substrate, indicated generally at 13. In the illustrated embodiment, the circuit device 3 is shown schematically, but it should be understood that each device can be any typical integrated circuit device. For example, microelectronic mechanical system (MEMS) devices, optoelectronic (OE) devices, and other microchips that can be used in electronic circuits. The module 1 shown in FIG. 1 includes a protective cap 15 formed of a conventional material (eg, metal, ceramic, or plastic). This cap is attached to the chip carrier substrate 13 by conventional means (eg, welding, soldering, brazing) to surround and protect the integrated circuit device 3. Alternatively, the cap 15 of the module 1 can have an access window (not shown) to allow light to pass through the cap. Alternatively, the module may not be provided with a cap.

  As can be seen in FIGS. 1 and 2, the integrated circuit device 3 has four stops 19 integrated with the device. These stops 19 protrude from the bottom surface of the device and come into contact with the substrate 13. In one embodiment, each stop is a solid cylindrical body made from the same semiconductor material as the circuit device 3 as part of the chip manufacturing process and disposed near each corner of the circuit device. As discussed in more detail below, the stop 19 limits the spacing of the chip 3 relative to the substrate 13 and ensures that the chip and the substrate are aligned in a parallel plane.

  In the embodiment of FIG. 2, the module 1 has eight sets of electrical connection pads (ie, bond pads) 23 on the integrated circuit device 3. This is for meshing with the corresponding electrical connection pads 27 on the substrate 13. Each connection pad 23 on the circuit device 3 is a metal pad formed on the surface of the device, and is arranged so as to contact a corresponding pad 27 on the opposite surface of the chip carrier substrate 13. Each of the electrical connection pads 23 and 27 is electrically connected to the circuit of the microchip 3 or the substrate 13 through normal means. As a result, electrical signals are transmitted and received through the pad. In the illustrated embodiment, the connection pads 23 are located near the periphery of the bottom (passive) surface 31 of the device 3, but it should be understood that these pads are on the top (active) surface of the chip. It can be arranged on 33. Also, more or fewer than eight pads 23, 27 can be provided without departing from the scope of the invention. It should be understood that the total number of connection pads 23, 27 on the chip 3 and the substrate 13 varies depending on the specific technology and application of the integrated circuit device, and hundreds or thousands of external Connection terminals are also present on the microchip and the substrate. Each connection pad 23 is arranged for attachment to a corresponding (combined) connection pad 27 on the substrate 13. For this reason, a conductive path is provided between the integrated circuit device and the substrate. As discussed in more detail below, each pair of mated connection pads 23, 27 on the chip 3 and substrate 13 is a cooperating capable of electrically and mechanically connecting the integrated circuit device to the chip carrier substrate. Connecting elements 37 and 39 (FIG. 3).

  As shown in FIG. 3, each electrical connection pad 23 on the integrated circuit device 3 has an outer surface 43 generally parallel to the device and comprises at least one, possibly more than one conductive connection element 37. . Each conductive connecting element comprises a first protrusion that protrudes from the flat outer surface of the pad. In the embodiment of FIGS. 3 and 4, each first protrusion 37 comprises a solid cylindrical body. The main body has a flat and circular free end 51 and an outer surface 53 having an axial length substantially orthogonal to the flat outer surface 43 of the connection pad 23. It should be understood that the protrusion 37 may have other shapes and configurations without departing from the scope of the present invention. In one embodiment, each protrusion 37 is formed as an integral part of the connection pad 23 and is made of a suitable metal or metal alloy (eg, copper or copper alloy). Each connection element 37 is connected to the microchip device 3 prior to metallization of the connection pads 23 using a normal manufacturing process such as microelectronic photolithography technology (ie, LIGA process or surface micromachining and etching). Preferably, the projections are formed of the same semiconductor material (eg, silicon, ceramic, or other suitable semiconductor material). After the manufacture of the microchip device 3, the protrusion 37 and the peripheral region on the bottom surface 31 of the device are metallized by a normal process such as vacuum metal deposition, electroless plating or electrolytic plating, and the metallized protrusion and the protrusion A conductive connection pad 23 having a flat outer surface 43 is formed. Instead, each connection pad 23 is a conventional microfabrication process, such as electroplating, sputtering, etc., that is well suited for making three-dimensional metal protrusions bonded to the flat surface 43 of the integrated circuit device side connection pad 23. Alternatively, it can be made of a solid metal processed by LIGA. In this alternative processing method, the metal protrusion 37 can be bonded to the connection pad 23 after a normal chip processing step is completed.

  Referring back to FIG. 3, each electrical connection pad 27 on the substrate 13 includes a plurality of spaced apart conductive connection elements 39. Each element 39 comprises a second protrusion extending from the flat outer surface 61 of the pad that is substantially parallel to the substrate. As can be seen in FIGS. 3 and 4, each second projection 39 comprises a solid cylindrical body. The main body has a flat circular free end 67 and an outer surface 69 having an axial length substantially perpendicular to the flat outer surface 61 of the connection pad 27. Each second protrusion 39 is preferably constructed similarly to the first protrusion 37 on the circuit device 3 and is made of conventional semiconductor material, metallized, and has a conductive outer surface 69. It should be understood that the protrusion 39 on the substrate side connection pad 27 is made of the same material using the same manufacturing process as described above for the first protrusion 37 on the integrated circuit device 3. That is. Also, the second protrusion 39 can have other shapes and configurations without departing from the scope of the present invention.

  As seen in FIGS. 3-6, the first protrusion 37 on the integrated circuit device 3 and the second protrusion 39 on the substrate 13 form an electrical and mechanical connection between the device and the substrate. Applicable to meshing. More specifically, the first and second protrusions 37 and 39 are in close frictional engagement with each other along their respective axial lengths when the circuit device 3 is mounted on the substrate 13. In order to do this, the size and shape are set. In one embodiment, the grouped four second protrusions 39 are spaced apart to form one open space for receiving one first protrusion 37. As a result, the axial outer surface 53 of the first protrusion comes into contact with the axial outer surface 61 of each of the four second protrusions. Alternatively, if the second protrusions 39 are arranged in another manner, more or less than four protrusions can contact the outer surface 53 of each first protrusion 37. The contact between the axial outer surface 53 of each first protrusion 37 and the axial outer surface 69 of each surrounding second protrusion provides a friction fit that provides a mechanical connection force that resists separation of the device 3 and the substrate 13. produce. It should be understood that the device and substrate, 3 and 13, respectively, are kept in contact by a surface suction force (eg, static friction force) common to microchip connections. Further, when the protrusions 37 and 39 are made of a metalized semiconductor material, the protrusions can be elastically deformed when engaged. In this case, each protrusion is bent by an arc of several degrees from a position orthogonal to the device 3 or the substrate 13 to facilitate insertion of the protrusion. The frictional surface attractive force and / or mechanical force generated by the engagement of the first and second protrusions 37, 39 allows the integrated circuit device without the need to apply adhesive or solder to the connection pads 23, 27. A connection force sufficient to hold 3 in a fixed position with respect to the substrate 13 is given. However, the connection force that keeps the integrated circuit device 3 and the substrate 13 in an electromechanical connection is sufficiently small so that the device can be removed and replaced without the need for extensive rework of the connection pads 23,27, It can be rearranged on the substrate. The device 3 is mounted on the substrate 13 by the engagement of the first and second protrusions 37, 39 during final component assembly or integrated circuit device testing.

  As shown in FIG. 6, the integrated circuit device 3 is attached to the substrate 13. In this case, the first protrusion 37 on the device and the second protrusion 39 on the substrate are completely meshed (that is, at least one of the free ends 51 and 67 of each protrusion is connected to the respective connection pad 23, 27 flat surfaces 43, 61). When each first protrusion 37 is completely inserted into the open space between the respective adjacent second protrusions 39, the contact area between the protrusions increases, and the mechanical connection force for holding the chip 3 on the substrate 13 is as follows. Become the maximum.

  Alternatively, device 3 may be an opto-electric or optical MEMS device that requires vertical alignment for the transfer of light between adjacent devices. As shown in FIGS. 2 and 7, the stops 19 are arranged at the four corners of the circuit device 3 and are in contact with the substrate 13. For this reason, the integrated circuit device is held at a desired distance D from the substrate. Stops 19 extending from the circuit device near each corner of the device are in contact with the substrate 13. For this reason, the device and the substrate are parallel to each other when the protrusions 37 and 39 are engaged with each other. Adjacent circuit devices (not shown) have the same stops 19 to align the circuit devices at the same height. For this reason, optical signals (i.e. light) are transferred between devices. Stop 19 also reduces the amount of overlap between the protrusions and reduces the amount of axial length of each protrusion in electrical and mechanical contact. The amount of overlapping axial length of each protrusion required for a particular integrated circuit varies depending on the size of the integrated circuit device and the electrical circuit requirements. Typically, the amount of overlap is in the range of 25% to 100% of the axial length of the protrusion.

  In one exemplary embodiment, each bond pad 23 on device 3 and each pad 27 on substrate 13 has a length of about 100 microns and a width of about 100 microns. Each first protrusion 37 and second protrusion 39 has a minimum length of about 12 microns and a minimum diameter of about 1 micron. Each stop 19 has a length of about 16 microns. In this case, the corresponding distance D (FIG. 7) between the device 3 and the substrate 13 is about 16 microns, and the corresponding overlap in the axial length of the mating projections 37, 39 is about 8 microns (each projection (66% of the total length in the axial direction). The minimum spacing between the protrusions 37, 39 is about 1 micron, and in one embodiment where the protrusions are arranged in 50 rows and 50 columns, the maximum number of protrusions is about 250. More preferably, a smaller number of protrusions 37, 39 can be used, each protrusion having a larger diameter. In one embodiment, a single first protrusion 37 having a diameter of about 100 microns and a length of about 12 microns is provided on the microchip device 3, and each has a diameter of about 30 microns and about 12 microns. Three second protrusions 39 having a length of micron are provided on the substrate 13.

  It should be understood that the first and second protrusions 37 and 39 described above can have other dimensions and can be arranged in other ways without departing from the scope of the present invention. It is. The amount of contact surface area between the first and second protrusions is directly proportional to the electrical conductivity between the protrusions and directly proportional to the mechanical connection force that holds the integrated circuit device 3 and the substrate 13 tightly. The number of protrusions 37, 39, the dimensional configuration of the protrusions, and the amount of protrusion axial length overlap will vary based on the particular application and the amount of electrical conductivity and mechanical connection force required. For example, high current applications require a large number of intermeshing protrusions 37,39. This is because a large amount of current can be transferred between the circuit device 3 and the substrate 13.

  In operation, the integrated circuit assembly 1 of the present invention is made by electrically and mechanically connecting the integrated circuit device 3 to the chip carrier substrate 13. The device 3 is electrically and mechanically connected to the chip carrier substrate 13 by engagement of at least one first protrusion 37 on the circuit device and at least two second protrusions 39 on the paired substrate. Has been. The frictional engagement between the first protrusion 37 and the second protrusion 39 creates a secure electrical and mechanical connection between the integrated circuit device 3 and the substrate 13. The chip carrier substrate 13 receives electrical signals from printed circuit boards (not shown) and other electronic circuit components. This electric signal is transferred to the integrated circuit device 3 through the contact between the conductive first protrusion and the conductive second protrusion 39. Instead, the assembly 1 is configured with a first protrusion 37 on the substrate 13 and a second protrusion 39 on the integrated circuit device 3. In this case, the electrical and mechanical connection between the device and the substrate is established through the engagement of the protrusions.

  FIG. 8 shows a second embodiment of the present invention, indicated generally at 201 with integrated circuit device side connection pads 203. The connection pad 203 of this embodiment is substantially the same as the connection pad 23 of the first embodiment. However, the pad of this embodiment includes the first protrusion 207. Each first protrusion 207 of the integrated circuit device side connection pad 203 has a solid truncated main body having a circular cross section. The body has a rounded free end or tip 215 and an outer surface 217 tapered to increase in diameter from the free end to the proximal end of the protrusion. Each first protrusion 207 is made of a metal or other conductive material as in the first embodiment, and meshes with a cylindrical second protrusion 39 (FIG. 5) on the substrate 13. It is configured. Instead, the first protrusion 207 is a second protrusion on the substrate that is identical in structure to the first protrusion, or a second protrusion having another shape and configuration that does not depart from the scope of the invention. It can also mesh with the protrusion. It should be understood that the rounded tip 215 of each protrusion 207 allows the first protrusion to be quickly and easily positioned between each second protrusion (FIG. 8) on the substrate 13 (ie, , Guide). The tapered outer surface 217 of each first protrusion 207 allows a tighter friction fit with the second protrusion 39 to increase the mechanical holding force upon further insertion of the device 3 toward the substrate 13. Arise. This embodiment 201 is particularly useful for applications requiring a durable and impact resistant electrical connection between the integrated circuit device 3 and the substrate 13.

  FIG. 9 shows a cross-sectional view of the third embodiment of the present invention, indicated generally at 301. This embodiment 301 is substantially the same as the first embodiment, but the first protrusion 305 on the circuit device and the second protrusion 307 on the substrate 13 have an oval or elliptical cross section. . In one embodiment, each oval first projection 305 is larger than the oval second projection 307 of this embodiment, but the first and second projections do not depart from the scope of this invention. , Can have other sizes, or can be arranged in other ways. It should be understood that the first and second protrusions 305, 307 of this embodiment can be formed of metal or other conductive material using the same process as described above for the first embodiment. That's what it means.

  10 and 11 of the present invention, shown generally at 401, with connection pads 403 on the integrated circuit device 3 (FIG. 1) and connection pads 405 on the substrate 3 (FIG. 1), as in the previous embodiment. The 4th Embodiment is shown. Each connection pad 403 on the circuit device 3 has a first protrusion 409, and the connection pad 405 on the substrate 3 has a second protrusion 413. Each protrusion 409, 413 has a polygonal cross section with a generally flat contact surface. In the particular embodiment of FIGS. 10 and 11, each first and second protrusion 409,413 has a solid parallelogram body extending from a respective electrical connection pad 403,405. The engagement of the first and second protrusions 409, 413 in this embodiment provides a larger contact area between the protrusions and allows a greater current carrying capacity between the device 3 and the substrate 13. It should be understood that the first and second protrusions 409 and 413 have other polygonal cross sections (eg, rectangles, squares, triangles, etc.) without departing from the scope of the present invention. It can be done.

  Referring to FIGS. 12 and 13, the integrated circuit device package shown generally at 701 includes an integrated circuit device 703 mounted on an interconnect substrate 707. As shown in FIG. 12, the package 701 is electrically connected to an electrical circuit board 711 (eg, a printed circuit board, ball grid array, or land grid array) by conductive connection elements 715 on the interconnect board 707. Connected mechanically and mechanically. In one embodiment, the conductive connection element 715 is placed in electrical contact with the conductive connection element 717 on the electronic circuit board 711 to allow electrical signals to pass to the integrated circuit device package 701. Although integrated circuit device 703 is shown schematically, it should be understood that any type of circuit device that has an active surface 719 and requires a protected enclosed space. It may be a circuit device (for example, a MEMS device or an OE device). The integrated circuit device 703 has electrical connection pads 723. This pad is arranged away from the periphery of the circuit device and is configured similarly to the pad 23 described above for the integrated circuit device 3 shown in FIGS. The connection pads 723 on the circuit device 703 shown in FIG. 12 are disposed on the active surface 719 of the chip. The chip typically has moving parts (not shown) that are actuated by electrical signals received from an electronic circuit board 711.

  Typically, the interconnect substrate 707 is made using the same chip assembly process and the same semiconductor material (eg, silicon) as the circuit device 703. Alternatively, the interconnect substrate can have a window (not shown) or can be made of a translucent material that allows light to pass through the interconnect substrate to the optical MEMS device 703. The interconnect substrate 707 has a first surface 741 applied for contact with the active surface 719 of the integrated circuit device 703 and a second surface 745 applied for electrical connection with the electronic circuit substrate 711. As best seen in FIGS. 14 and 15, the interconnect substrate 707 has multiple sets of electrical connection pads. Each set comprises a first pad 749 on the first surface of the substrate and a second pad 753 on the second surface of the substrate. Each electrical connection pad 749, 753 is preferably disposed near the periphery of the interconnect substrate 707. As best seen in FIG. 13, the connection pads 749, 753 of the interconnect substrate 707 are electrically connected by metallized vias 759 that penetrate the interconnect substrate. The connection pads 749 on the interconnect substrate 707 are arranged to contact the corresponding pads 723 on the active surface 719 of the integrated circuit device 703. Further, the pad 753 on the second surface 745 of the interconnection substrate is applied to the connection with the electrical connection pad 717 of the electronic circuit substrate 711.

  In one embodiment, the conductive connection elements 715 on the interconnect substrate 707 comprise conductive connection protrusions similar to the connection elements 37 described above for the integrated circuit device 3 of FIG. Each protrusion 715 may be a metallized protrusion integrally formed with the electrical connection pad 753 or a metal protrusion coupled to the connection pad by a normal manufacturing process. As can be seen in FIGS. 12 and 14, the spaced apart conductive connection element 717 comprises a protrusion similar to the connection element 39 described above for the previous embodiment. The protrusions 715 on the interconnect substrate 707 and the protrusions 717 on the electronic circuit board 711 are applied to meshing to form an electrical and mechanical connection between the chip scale package 701 and the electronic circuit board. It should be understood that the protrusions 715 on the interconnect substrate 707 and the protrusions 717 on the electronic circuit board 711 can be integrated into any of the embodiments of the conductive connection elements discussed above or integrated circuit devices. Any of the other connection elements commonly used to connect to a circuit board can be provided.

  As best seen in FIGS. 14 and 15, the first surface 741 of the interconnect substrate 707 has an outer edge 773 for sealing contact with the active surface 719 of the circuit device 703 along the peripheral edge of the interconnect substrate. Have. It should be understood that the interconnect substrate 707 and the integrated circuit device 703 are bonded by a conventional wafer bonding method commonly used in the semiconductor industry (eg, adhesive bonding, fusion bonding, or anode bonding). Is to get. The first surface 741 of the interconnect substrate 707 has a shoulder 777 adjacent to the outer edge 773. This shoulder supports each electrical connection pad 749 that mates with a corresponding electrical connection pad 723 of the integrated circuit device 703. In the embodiment of FIG. 15, each electrical connection pad 749 on the first surface 741 of the interconnect substrate 707 has a flat contact plane. This contact plane is combined with a flat contact plane for each electrical connection pad 723 on the integrated circuit device 703. Interconnect substrate 707 has a recess 781 adjacent to shoulder 777. This recess forms a space enclosed by the package when the outer edge 773 contacts the active surface 719 of the integrated circuit device 703. In the illustrated embodiment, the recess 781 is disposed on the interconnect substrate 707 and comprises about 60% to 75% of the surface area of the interconnect substrate. It should be understood that more than one recess 781 of varying size can exist on the interconnect substrate 707. Also, the integrated circuit device 703 can be configured to have an active surface 719 with a recess similar to the recess 781. In this case, the first surface 791 of the interconnect substrate 707 is substantially flat.

  FIG. 16 illustrates a second embodiment of an integrated circuit device package indicated generally at 801. This embodiment 801 is substantially the same as the first embodiment of the package 701. However, the electrical connection pads 805 on the first surface 741 of the interconnect substrate 707 include pointed protrusions or teeth 809 that contact the electrical connection pads 723 on the integrated circuit device 703. When the circuit device 703 is coupled to the interconnect substrate 707, the pointed protrusions 809 are embedded in the electrical connection pads 723 on the integrated circuit device to keep the integrated circuit device in electrical connection with the interconnect substrate 707. Gives additional mechanical power to do. It should be understood that the protrusions 809 may have different sizes and shapes (eg, cylindrical protrusions with blunt ends) without departing from the scope of the present invention.

  FIG. 17 illustrates a third embodiment of an integrated circuit device package, indicated generally at 831. This embodiment 831 is substantially the same as the first embodiment of the package 701. However, the electrical connection pad 835 on the first surface 741 of the interconnect substrate 707 includes one or more conductive springs 839 extending from the connection pad. The spring 839 allows an electrical connection between the integrated circuit device 703 and the interconnect substrate 707 when the circuit devices are slightly misaligned. For this reason, the flat surface of the electrical connection pads 835 on the interconnect substrate 707 is not slightly parallel to the flat surface of the electrical connection pads 723 on the circuit device. The spring 839 is preferably integrally formed with the connection pad 835 using conventional spring metal materials (eg, molybdenum and chrome) using conventional assembly techniques. Reference is made to US Pat. Nos. 6,560,851 and 5,613,861. These are hereby incorporated by reference for all purposes and for conventional microspring materials and assembly processes.

  FIG. 18 shows a fourth embodiment of an integrated circuit device package, indicated generally at 851. This embodiment 851 is substantially the same as the first embodiment of package 701, but includes an interconnect substrate 855. This substrate has conductive elements with solder balls 859 instead of conductive protrusions 715 (FIG. 12). By placing the package 851 on the substrate and heating the package to reflow the solder balls 859, the package 851 is mounted directly on the conductive connection pads (not shown) of the electronic circuit board 711 by conventional means. Is done. Alternatively, the conductive connecting element 859 of this embodiment can be made of other materials. For example, a conductive adhesive that can be used to electrically and mechanically connect the integrated circuit device package 851 to the electronic circuit board 711.

  With reference to FIGS. 19-21, the integrated circuit device package 701 shown in FIGS. 12-18 may be formed by a wafer level assembly process resulting in a plurality of individual integrated circuit device packages. In this process, an integrated circuit device wafer 871 having a plurality of integrated circuit devices 703 is manufactured. Each device has an active surface 719 and a plurality of electrical connection pads 723 on the active surface. As shown in FIG. 19B, the interconnect substrate wafer 875 is fabricated to have a plurality of surfaces corresponding to the outer edge 773, shoulder 777, and recess 781 described above for the individual integrated circuit device package 701. The interconnect substrate wafer 875 includes a plurality of electrical connection pads 749 made on the shoulder 777 of the first surface 741 of the substrate and a plurality of conductive connection elements 715 made on the second surface 745 of the wafer. Have It should be understood that the conductive connection element 715 is formed by any of the methods described above for the conductive connection element 37 on the integrated circuit device 3. The wafers 871 and 875 are manufactured by a normal wafer manufacturing method. Reference is made to US Pat. Nos. 6,475,881, 6,159,826, 5,981,361 and 5,685,885. These are hereby incorporated by reference for all purposes and for the normal wafer assembly process. As shown in FIG. 20, the circuit device wafer 871 and the interconnect substrate wafer 875 are bonded together by a conventional bonding method. In this case, the outer edge 773 protruding from the first surface 741 of the interconnect substrate wafer 875 is placed in sealing contact with the active surface 719 of the integrated circuit device wafer 871. Also, the wafers 871 and 875 are aligned before bonding. In this case, the electrical connection pads 723 and 749 are pressed together to make an electrical connection between the integrated circuit device wafer and the interconnect substrate wafer. After bonding, the joined wafers 871 and 875 are cut by a normal dicing method (for example, laser dicing or sawing). In one embodiment, wafers 871 and 875 are cut along cut line 879. This cut line passes through the edge structure on the interconnect substrate wafer corresponding to the outer edge 773 of the wafer 875 in contact with the integrated circuit device wafer 871. The cut line 879 preferably passes through the centers of these edge structures. The cut wafer produces a discrete integrated circuit device package 701 (FIG. 21). The package has a conductive connection element 715 ready for direct electrical and mechanical connection to the electronic circuit board 711 without requiring additional processing.

  The package 701 of the present invention is a chip scale package (CSP) close to the size of the integrated circuit device 703, which is an additional circuit board required when compared to a bare chip mounted on the board by direct chip attachment. The mounting area is very small. It should be understood that the package 701 occupies a larger substrate mounting area than the bare integrated circuit device 703 by an amount approximately equal to the width of the outer edge 773 of the interconnect substrate 707. The package 701 preferably has a substrate mounting area that is approximately 1 to 20% larger than the mounting area of the bare integrated circuit device. More preferably, the substrate mounting area of this package is approximately 1-10% larger than the substrate mounting area of the bare integrated circuit device. The substrate mounting area of this package is most preferably about 1% larger than the substrate mounting area of the bare integrated circuit device.

  In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results are obtained. The frictional engagement between the first protrusion 37 and the second protrusion 39 of the chip module 1 allows the assembly and attachment of the integrated circuit device 3 to the substrate 13 without the application of heat and the resulting thermal stress. And The first protrusion 37 and the second protrusion 39 on the circuit device 3 and the substrate 13 allow the device to be easily removed from the substrate after testing and reconnected to the substrate without extensive rework. Also, the frictional engagement between the first and second protrusions 37, 39 allows for easy repair and replacement of the integrated circuit device 3 in the final assembly. The first and second protrusions 37 and 39 can be easily manufactured during a chip or substrate manufacturing process. Alternatively, these protrusions can be assembled as an additional step after completion of the chip or substrate assembly process. The integrated circuit device package 701 can be manufactured with a simple wafer level process that does not require additional processing for electrical connection from the package to the circuit board 711. The integrated circuit device package 701 provides an enclosed space for protecting the integrated circuit device 703 and minimizes the circuit board mounting area. Conductive connection elements 715, 859 on the integrated circuit device packages 701, 851 allow the package to be easily mounted on and removed from the electronic substrate 711.

  Since various modifications can be made to the above configuration without departing from the scope of the present invention, all matters included in the above description and shown in the accompanying drawings should be construed for the purpose of description. And not for limitation. For example, the first and second protrusions 37, 39 may have alternative shapes and sizes that allow for frictional engagement that holds the integrated circuit device 3 and the substrate 3 in electrical and mechanical contact. The first and / or second protrusions 37 and 39 may be formed integrally with the respective electrical connection pads 23 and 27, or may be configured as an integrated part of the integrated circuit device 3 or the substrate 13. it can. Furthermore, the first and / or second protrusions 37 and 39 may be finger-like protrusions having a common base attached to or integrally formed with the respective electrical connection pads 23 and 27.

  When introducing elements of the present invention or its preferred embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there is one or more of these elements. . The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

It is the elevation view made into the partial cross section of the chip module which shows the assembly of this invention. It is a disassembled perspective view of the integrated circuit device and board | substrate of the said module. FIG. 2 is an enlarged perspective view of an integrated circuit device side electrical connection pad and a substrate side electrical connection pad in the first embodiment of the assembly. FIG. 4 is a cross-sectional view of a plane including line 4-4 in FIG. 3. It is sectional drawing in the surface containing the line 5-5 of FIG. FIG. 6 is a cross-sectional view similar to FIG. 5, but showing a state where the integrated circuit device side electrical connection pads and the substrate side electrical connection pads are completely engaged. 1 is an enlarged side elevational view of an integrated circuit device and a substrate of a first embodiment. It is an expansion perspective view of the integrated circuit device side electrical connection pad of 2nd Embodiment of this invention. FIG. 5 is a cross-sectional view similar to FIG. 4, but illustrating a third embodiment of the present invention. It is an expansion perspective view of the integrated circuit device side electrical connection pad and board | substrate side electrical connection pad in 4th Embodiment of this invention. It is sectional drawing in the surface containing the line 11-11 of FIG. 1 is an elevational view of an integrated circuit device package of the present invention attached to an electronic circuit board. FIG. FIG. 13 is a cross-sectional view of the package of FIG. 12 removed from the electronic circuit board. It is an exploded elevation view of the package removed from the electronic circuit board. FIG. 2 is a fragmentary enlarged view of an integrated circuit device and interconnect substrate in partial cross section of the first embodiment of the package. FIG. 6 is a fragmentary enlarged view of an integrated circuit device and interconnect substrate in partial cross section of a second embodiment of the package. FIG. 6 is a fragmentary enlarged view of an integrated circuit device and interconnect substrate in partial cross section of a third embodiment of the package. FIG. 14 is a cross-sectional view similar to FIG. 13, but showing a fourth embodiment of the present invention. 1 is a perspective view of an integrated circuit device wafer and an interconnect substrate wafer used in a process for forming an integrated circuit device package of the present invention. FIG. It is an enlarged side elevational view of an integrated circuit device wafer. FIG. 3 is an enlarged side elevation view of an interconnect substrate wafer. 1 is a perspective view of an integrated circuit device wafer and an interconnect substrate wafer connected by the process of this invention. FIG. It is a perspective view of the integrated circuit device package created by this process.

Explanation of symbols

Corresponding parts are designated by corresponding reference numerals throughout the drawings.
DESCRIPTION OF SYMBOLS 3 Integrated circuit device 13 Chip carrier board | substrate 23,27 Electrical connection pad 37 1st protrusion 39 2nd protrusion 701 Package 707 Interconnection board 711 Electronic circuit board

Claims (26)

A substrate,
An integrated circuit device adapted to be electrically and mechanically connected to the substrate;
Electrical connection pads on the integrated circuit device and on the substrate and applied to contact each other when the circuit device and the substrate are connected;
The connection pad has at least one first protrusion on one of the device and the substrate, and at least two second protrusions on the other of the device and the substrate, each protrusion being respectively Each having an axial length extending from the outer surface of the connection pad,
The at least one first protrusion and the at least two second protrusions are sized and shaped to provide a tight friction fit along their axial length when engaged with each other. An assembly having a respective outer surface thereby creating an axial contact area between the respective protrusions to establish an electrical and mechanical connection between the device and the substrate .   The assembly of claim 1, wherein the at least one first protrusion is on the integrated circuit device and the at least two second protrusions are on the substrate.   The assembly of claim 1, wherein the at least one first protrusion is a headless protrusion.   The at least one first protrusion comprises a solid cylindrical body integrally formed with the circuit device or substrate and comprises a metal outer surface for contacting the at least two second protrusions. The assembly according to 1.   The assembly of claim 4, wherein the at least two second protrusions comprise a solid cylindrical body and are spaced apart to form an open space that receives the at least one first protrusion.   The at least one first protrusion is adapted for insertion into the open space, wherein the device and the substrate are respectively axes of the at least one first protrusion and the at least two second protrusions. 6. The assembly of claim 5, wherein the assembly is held in an electrically and mechanically connected state by a friction fit between directional lengths.   The assembly of claim 1, wherein the at least one first protrusion is a truncated body.   The assembly of claim 1, wherein the at least one first protrusion and the at least two second protrusions have an elliptical cross section.   The assembly of claim 1, wherein the at least one first protrusion and the plurality of second protrusions have a polygonal cross-section. An integrated circuit device having an active surface and having at least one electrical connection pad thereon;
An interconnection substrate for mounting the integrated circuit device on the electronic circuit substrate,
The interconnect substrate is applied to electrical and mechanical connections between the electronic circuit board and a first surface applied to be combined with an active surface of the integrated circuit device to form an enclosed space. A second surface,
The interconnect substrate has at least one set of electrical connection pads, each set being adapted for electrical connection with at least one electrical connection pad on the integrated circuit device. A first electrical connection pad on one surface; and a second electrical connection pad on a second surface of the interconnect substrate electrically connected to the first connection pad, the interconnect substrate. The integrated circuit device package, wherein the second electrical connection pads on the second surface of the integrated circuit device are applied for electrical and mechanical connection with the electronic circuit board.   The package according to claim 10, wherein the second electrical connection pad is a solder ball for electrical and mechanical connection with the electronic circuit board.   The package of claim 10, wherein the second electrical connection pad is a protrusion having a substantially rigid cylindrical body extending from an outer surface of the second electrical connection pad.   The second electrical connection pad comprises at least one conductive connection element on the interconnect substrate and is further adapted to be combined with at least one conductive connection element on the interconnect substrate. Two conductive connecting elements on the electronic circuit board, the conductive connecting elements on the electronic circuit board and the interconnect board being sized and shaped for a close intimate frictional fit The package of claim 10, thereby establishing an electrical and mechanical connection between the package and the electronic circuit board.   The package of claim 10, wherein the first conductive connection pad on the interconnect substrate comprises at least one protrusion adapted for contact with an electrical connection pad of the integrated circuit device.   The package of claim 10, wherein a first conductive connection pad on the interconnect substrate comprises at least one spring applied in contact with an electrical connection pad of the integrated circuit device.   The first surface of the interconnect substrate includes an outer edge for sealing contact with the integrated circuit device, and a recess that forms the enclosed space when the outer edge contacts the integrated circuit device. The package according to 10.   The package of claim 16, wherein the first surface of the interconnect substrate further comprises a shoulder for disposing a first conductive connection pad of the interconnect substrate between the recess and the outer edge. A process for forming an integrated circuit device package comprising:
Creating an integrated circuit device wafer having an active surface;
Creating an interconnect substrate wafer such that the wafer has electrical connection pads on its opposite side and a concave surface;
Electrically and mechanically connecting the integrated circuit device wafer and the interconnect substrate wafer, the two wafers are enclosed between an active surface of the integrated circuit device wafer and a recessed surface of the interconnect substrate wafer. Forming a space,
Dicing the integrated circuit device wafer and the interconnect substrate wafer to form one or more individual integrated circuit device packages.   19. Creating the interconnect substrate wafer includes configuring the interconnect substrate wafer to have at least one conductive connection element for electrical and mechanical connection to an electronic circuit board. The process described in   The process of claim 19, wherein the dicing step includes cutting the bonded wafer into the one or more discrete integrated circuit device packages. An interconnect substrate for mounting an integrated circuit device on an electronic circuit substrate,
A first surface applied to form an enclosed space in combination with an active surface of the integrated circuit device; a second surface applied to electrical and mechanical connection with the electronic circuit board;
A first electrical connection pad on a first surface of the interconnect substrate and applied for electrical connection with the integrated circuit device;
A second electrical connection pad on the second surface of the interconnect substrate and electrically connected to the first connection pad;
The interconnect board according to claim 2, wherein the second electrical connection pad on the second surface of the interconnect board is applied to an electrical and mechanical connection with the electronic circuit board.   The interconnect substrate of claim 21, wherein the first surface of the interconnect substrate comprises an outer edge for sealing contact with the integrated circuit device.   23. The interconnect substrate of claim 22, wherein the first surface of the interconnect substrate further comprises a recess that forms the enclosed space when the outer edge contacts the integrated circuit device.   The interconnect substrate according to claim 22, wherein the first surface of the interconnect substrate further includes a shoulder for disposing the first conductive connection pad between the recess and the outer edge.   The interconnect substrate of claim 22, wherein the first conductive connection pad comprises at least one protrusion adapted for contact with an electrical connection pad on the integrated circuit device.   The interconnect substrate of claim 22, wherein the first conductive connection pad comprises at least one spring applied in contact with an electrical connection pad on the integrated circuit device.

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